TSPAN32 suppresses chronic myeloid leukemia pathogenesis and progression by stabilizing PTEN

• Published in: Signal transduction and targeted therapy 2023-03, Vol.8 (1), p.90-90, Article 90
• Main Authors: Qiu, Qiang, Sun, Yuanyuan, Yang, Linyu, Li, Qingqing, Feng, Yunyu, Li, Mengyuan, Yin, Yuexia, Zheng, Li, Li, Ning, Qiu, Huandi, Cui, Xue, He, Wei, Wang, Bochuan, Pan, Cong, Wang, Zi, Huang, Juan, Sample, Klarke M., Li, Zhihui, Hu, Yiguo
• Format: Article
• Language: English
• Subjects: 1-Phosphatidylinositol 3-kinase; 631/532/1542; 631/67/1990; AKT protein; Animal models; Animals; BCR-ABL protein; Cancer Research; Cell Biology; Cell self-renewal; Chronic myeloid leukemia; Ectopic expression; Fusion protein; Imatinib; Imatinib Mesylate - pharmacology; Internal Medicine; Leukemia; Leukemia, Myelogenous, Chronic, BCR-ABL Positive - drug therapy; Leukemia, Myelogenous, Chronic, BCR-ABL Positive - genetics; Leukemia, Myelogenous, Chronic, BCR-ABL Positive - metabolism; Medicine; Medicine & Public Health; Mice; Myeloid leukemia; Oncology; Pathogenesis; Pathology; Phosphatidylinositol 3-Kinases - genetics; Phosphatidylinositol 3-Kinases - metabolism; Proto-Oncogene Proteins c-akt - metabolism; PTEN Phosphohydrolase - metabolism; PTEN protein; Tetraspanins - metabolism
• ISSN: 2059-3635; 2095-9907; 2059-3635
• DOI: 10.1038/s41392-022-01290-7

We report herein that TSPAN32 is a key node factor for Philadelphia (Ph + ) leukemia pathogenesis. We found that TSPAN32 expression was repressed by BCR-ABL and ectopic TSPAN32 expression upon Imatinib treatment inhibited the proliferation of Ph + cell lines. Tspan32 overexpression significantly prevented BCR-ABL induced leukemia progression in a murine model and impaired leukemia stem cell (LSC) proliferation. LSCs represent an obstacle for chronic myeloid leukemia (CML) elimination, which continually replenish leukemia cells and are associated with disease relapse. Therefore, the identification of essential targets that contribute to the survival and self-renewal of LSCs is important for novel curative CML. Mechanistically, TSPAN32 was shown to interact with PTEN, increased its protein level and caused a reduction in PI3K-AKT signaling activity. We also found that TSPAN32 was repressed by BCR-ABL via the suppression of an important transcription factor, TAL1 . Ectopic expression of TAL1 significantly increased TSPAN32 mRNA and protein level, which indicated that BCR-ABL repressed TSPAN32 transcription by decreasing TAL1 expression. Overall, we identified a new signaling axis composed of “BCR-ABL-TAL1-TSPAN32-PTEN-PI3K-AKT”. Our findings further complement the known mechanisms underlying the transformation potential of BCR-ABL in CML pathogenesis. This new signaling axis also provides a potential means to target PI3K-AKT for CML treatment.